JP3206770B2 - Music generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION This invention, for example, easy frequency characteristics of the musical tone such that desired frequency characteristics depending on the environment
The present invention relates to a sound generator .

[0002]

2. Description of the Related Art Conventionally, an electronic musical instrument having a built-in speaker and having functions such as an equalizer and an effector has been known. In this electronic musical instrument, the frequency characteristics of a musical tone to be output can be freely changed by adjusting and setting various parameters such as an equalizer.

When the listener (player) is away from the speaker, the musical sound reaching the listener's ear may not only be directly transmitted from the speaker but also may be reflected on a wall in the room. Some bands are amplified or attenuated. In other words, the frequency characteristic of the musical sound generated from the speaker changes depending on the external environment such as the indoor environment before reaching the listener's ear. Therefore,
The listener hears a musical tone having a frequency characteristic different from that actually output from the speaker. Therefore, the listener adjusts various parameters such as an equalizer in advance in order to correct the frequency characteristic change of the musical sound so that the frequency characteristic of the musical sound reaching the ear becomes a desired one.

[0004]

However, every time there is a change in the external environment, such as a change in the listening place or a change in the installation place, it is necessary to adjust the musical sound so as to have a desired frequency characteristic. In this case, since the listener must reset various parameters, there is a problem that a lot of trouble and time are required. SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to control the frequency characteristics of a tone signal to be output so as to compensate for changes in frequency characteristics due to the environment, so that a tone reaching a listener can be achieved. It is an object of the present invention to provide a musical sound generating device that makes a desired sound .

[0005]

According to the first aspect of the present invention,
In order to solve the above-mentioned problem, a musical sound signal generating means for generating a predetermined musical sound signal is provided, and in a musical sound generating apparatus for giving a desired frequency characteristic to the musical sound signal generated by the musical sound signal generating means, a filter coefficient is used. filter means for filtering said tone signal at a defined characteristic (e.g., a filter 7 in the embodiment) and, either the filtered tone signal by the tone signal generated in the musical tone signal generating means and the filter means on the other hand Based on the tone signal of
An output unit (for example, speaker 11 or the like in the embodiment) for outputting a musical tone;
Input means (for example, a microphone 12 or the like in the embodiment) for converting the signal into a signal; and supplying the tone signal generated by the tone signal generating means to the output means prior to giving a desired frequency characteristic to the tone signal. , filtered of the generated musical tone signal and the filter means of the signal and the musical tone signal generating means output from said input means in response thereto
Estimating means (for example, the parameter supply unit 6 in the embodiment) for estimating the transfer characteristic (H ′) based on the obtained tone signal.
2) and data supply means for storing a plurality of data relating to a desired frequency characteristic and controlling the frequency characteristic of the tone signal generated by the tone signal generating means based on data selected from the plurality of data. For example, the data supply unit 5) in the embodiment, and the tone signal filtered by the filter means is supplied to the output means, and the signal (h (n)) output from the input means and the data The signal (h (n)) output from the input means and the signal (h (n)) are output so that the error signal (e) obtained from the signal (d (n)) whose frequency characteristic is controlled by the supply means has a minimum value. The signal (d (n)) whose frequency characteristic is controlled by the data supply unit and the tone signal generation unit to which the transfer characteristic (H ′) estimated in advance by the estimation unit are added are generated.
Filter control means for calculating and generating the filter coefficient from a musical tone signal and supplying the filter coefficient to the filter means (for example, the parameter supply unit 62 and the estimated value provision unit 6 in the embodiment)
3) is provided. According to a second aspect of the present invention, in the tone generating apparatus of the first aspect, the filter control means performs the calculation and generation of the filter coefficient by a least square method. Furthermore, the invention according to claim 3 is the musical sound generating device according to claim 1, further comprising convergence speed setting means for arbitrarily setting the convergence speed of the filter coefficient, wherein the filter means sets the convergence speed. The filter coefficient is calculated and generated according to the convergence speed set by the means. According to a fourth aspect of the present invention, in the musical sound generating device of the first aspect, the data supply means selects frequency characteristic data corresponding to a genre from a plurality of stored frequency characteristic data. It is characterized by doing.

[0006]

According to the configuration of the first aspect of the present invention, the tone output by the output means is changed in its frequency characteristic by the external environment, and then taken in again by the input means and converted into a signal. You. Then, the estimating means
The filter control unit estimates the transfer characteristic and calculates and generates a filter coefficient from the data in the storage unit and the transfer characteristic estimated by the estimation unit, and controls the filter unit. Based on this filter coefficient, the filter means changes the frequency characteristics of the tone signal. The supply means supplies the tone signal filtered by the filter means to the output means. Further, a plurality of data indicating desired frequency characteristics are stored in the storage means in advance, and any one of the data is selected according to the selection operation, so that the musical sound reaching the listener can be converted to the desired frequency characteristics. It is possible to control so that As described above, according to the present invention, a plurality of data relating to a desired frequency characteristic are stored, arbitrary data can be selected from the data, and the selected data and the transfer characteristic estimated by the estimating means are stored. Since a filter coefficient is calculated and generated from the above and supplied to the filter means, it is possible to give an arbitrary frequency characteristic to the musical sound, and to give an arbitrary frequency characteristic to the musical sound and change the frequency characteristic due to the indoor environment. Can be realized by one filter, and the configuration can be simplified. Also,
According to the present invention, at the time of characteristic estimation, the tone signal generated by the tone signal generating means is output from the output means, and after the characteristic estimation is completed, the tone signal filtered by the filter means is output from the output means. Since the filter does not pass through the filter when estimating the characteristic, it is possible to prevent the signal from being excessively deteriorated. Furthermore, according to the configuration of claim 2
For example, the filter control means uses a least squares method.
Calculates the filter coefficient that minimizes the error signal e.
I do. Further, according to the configuration of claim 3, the flange is provided.
Setting means that can arbitrarily set the convergence speed of the filter coefficient
A filter section for calculating and generating the filter control means
Numbers converge at minimum point without oscillation in adaptation process
Next, the convergence speed is adjusted . Claim 4
According to the configuration of the first aspect, the data supply unit stores the stored multiple
From the frequency characteristic data
Ideal frequency characteristic data for the music sound heard by the listener
Select the data and output the tone signal corresponding to this data.
Add frequency characteristics.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing the electrical configuration of the electronic musical instrument of this embodiment. In this figure, reference numeral 1 denotes a keyboard device composed of a keyboard and a switch corresponding to each key. The keyboard device detects pressing and releasing of a key operated by a player, and performs signal key-on KON and key releasing corresponding to the key pressing. A corresponding key-off KOFF, a signal key code KC indicating a pitch corresponding to a key depression, and the like are generated.

Reference numeral 2 denotes an operation panel for setting timbre, rhythm, and the like. The operation panel 2 includes, as shown in FIG.
Switch 2 ₁ to 2 ₃ to select a rhythm switch 2 ₄ for instructing start / stop of the rhythm, and the switch 2 _{5-2 8} for selecting a tone color is provided each, and then the setting and selection of these switches The signal shown is generated.
That is, these signals are START / STOP corresponding to a rhythm start / stop instruction, a timbre code TC indicating a timbre to be emitted, and a genre code JC corresponding to a rhythm type.

Returning to FIG. Reference numeral 3 denotes a tone signal generator for generating a tone signal of a tone corresponding to the key code KC and a tone color corresponding to the tone color code TC in accordance with the key-on KON and the key-off KOFF. S is supplied to one input terminal. Meanwhile, 4 is a rhythm signal generating unit, when it is instructed rhythm started by the switch 2 _4, and generates a rhythm signal corresponding to a genre code JC, supplied to the other input terminal of the adder S.

In the adder S, the tone signal and the rhythm signal are added and supplied to the following input terminals. These input terminals are the input terminals B of the data supply unit 5, the operation unit 6, the filter 7, and the selector 8. Here, the adder S
Is defined as x (n) (n represents time slot numbers 0, 1, 2,... Corresponding to the sampling period). The data supply unit 5 stores an ideal frequency characteristic of a musical sound to be listened to by a listener for each genre selectable on the operation panel 2 and has, for example, a filter, and a genre code JC in the addition result x (n). And assigns a frequency characteristic based on the signal d (n).
To supply. Here, the ideal frequency characteristic for each genre is, for example, desirably a uniform characteristic over the entire region in the case of jazz, and a characteristic in which the high region is emphasized in the case of rock. Say etc.

The operation unit 6 includes an adder, a parameter supply unit, and an estimated value application unit, which will be described later. The arithmetic unit 6 generates an error signal e, which will be described later, from the signals supplied to the respective input terminals by these units, and a filter 7 based on the error signal e.
, And outputs a signal SLTA for controlling the selection of the selector 8. The filter 7 controls the frequency characteristic of the addition result x (t) based on the multiplication coefficient, and supplies this output signal to the calculation unit 6 and the input terminal A of the selector 8.

The selector 8 selects and outputs one of the data supplied to the input terminals A and B based on the signal SLTA supplied to the select terminal SA. At this time, the input terminal A is selected. The output of the selector 8 is supplied to a D / A converter 9.
After being converted into an analog signal, the signal is amplified by the amplifier 10 and output as a musical tone through the speaker 11. The musical sound from the speaker 11 is converted into an electric signal by the microphone 12, amplified by an amplifier 13, further converted into a digital signal by an A / D converter 14, and supplied to the arithmetic unit 6. Here, the microphone 12 is installed at a place where a musical sound is listened.

Next, the detailed configuration of the filter 7 will be described with reference to FIG.
This will be described with reference to FIG. In this figure, D is a delay element that delays the input data by one sampling cycle. Here, assuming that m is a positive integer, (m-1) delay elements D are cascade-connected as shown in this figure, and a general delay result x (ni) (i = 0)
~m-1) are respectively supplied to the multiplier M _i. Each of the multipliers M ₀ ~M _m-1 is the coefficient supplied from the operation unit 8 w a (0) ~w (m-1 ) intended to multiply each. The multiplication results of the multipliers M _{0 to} M _m−1 are added by the adder A and supplied as a signal y (n) of the filter 7. In such a configuration of the filter 7,
The signal y (n) is as follows.

[0014]

(Equation 1)

That is, in the filter 7, the coefficient w (0)
~ W (m-1), the addition result x
The frequency characteristic of (n) can be changed.

Next, the operation of this embodiment will be described. First, in this embodiment, a transfer characteristic H between the speaker 11 and the microphone 12 is determined to obtain an estimated characteristic H ′. Thereafter, in the embodiment, the tone output from the speaker 11 is given an inverse characteristic of the estimation characteristic H 'in advance to compensate for a change in the frequency characteristic due to the external environment. Hereinafter, these will be described in detail.

First, in order to estimate the transfer characteristic H, the arithmetic unit 6 sets the signal SLTA to "0" and causes the selector 8 to select the input terminal B. At this time, in this embodiment, a musical tone signal based on keyboard performance or automatic rhythm is used as the addition result x (n). This is because a keyboard performance sound or an automatic rhythm sound can be generated over a wide frequency band. For example, a noise generator may be provided, and a white noise signal having flat characteristics over the entire frequency band may be used. FIG. 2 is a simplified diagram of the configuration of FIG. 1 in this state, in particular, a portion subsequent to the adder S. For convenience of explanation, portions where the frequency characteristics do not change (selector 8, D / A converter 9, amplifier 10) , 13 and the A / D converter 14) are omitted. The same parts as those in FIG. 1 are denoted by the same reference numerals.

As shown in FIG. 1, when the input terminal B is selected by the selector 8, the addition result x (n) is supplied to the filter 7 and the arithmetic unit 6 and is sounded by the speaker 11. At this time, assuming that the signal taken by the microphone 12 is h (n), this signal h
(N) is obtained by adding the transfer characteristic H to the addition result x (n).

Next, the arithmetic section 6 calculates an error signal e in the adder 61 such that e = h (n) -y (n) and supplies it to the parameter supply section 62. By setting a set of multiplication coefficients w (i) of the filter 7 such that the error signal e is minimized, the transfer characteristic H can be estimated. In general, the error signal e
In order to minimize the square of, the filter coefficient w ′ (i) to be newly supplied may be calculated by an adaptation process using the least squares method (LMS method), that is, by using the following equation. It is known.

[0020]

(Equation 2) Where i = 0 to m−1

In this equation, μ is a coefficient for determining the convergence speed of the multiplication coefficient w (i). For example, when the value of the coefficient μ is very small, it converges on the minimum point without vibration in the adaptation process, but the adaptation speed becomes slow. On the other hand, the coefficient μ
Is very large, each step in the adaptation process may overshoot and diverge, but the adaptation speed becomes faster. Such a value of the coefficient μ is set to an appropriate value by a switch volume (not shown) or the like. Although x (n−i) is obtained by sequentially storing the addition result x (n) input to the parameter supply unit 62, each delay result of the filter 7 may be used. In this way, the set of the multiplication coefficient w (i) of the filter 7 that minimizes the error signal e is stored in the storage unit (not shown) in the arithmetic unit 6, and the transfer characteristic H is estimated. The estimated characteristic of the transfer characteristic H estimated in this manner is defined as H ′.

After the estimation of the transfer characteristic H is completed, the arithmetic unit 6 sets the signal SLTA to "1" and causes the selector 8 to select the input terminal A. At this time, an addition signal of the rhythm sound generated by the rhythm signal generation unit 4 and the musical sound signal generation unit 3 is used as the addition result x (n). That is, a normal performance sound is used. FIG. 3 is a simplified version of the configuration of FIG. 1 in this state, and the same parts as those in FIG. 1 are denoted by the same reference numerals. As shown in this figure, the addition result x (n) is
The data is supplied to the filter 7, the operation unit 6, and the data supply unit 5. The addition result x (n) supplied to the data supply unit 5 is given a frequency characteristic corresponding to the genre code JC supplied from the operation panel 2 to the data supply unit 5, and added as a target signal d (n). It is supplied to one input end of the device 61. Here, assuming that the frequency characteristic corresponding to the genre code JC is D, d (n) is d (n) = D · x (n).

The addition result x supplied to the filter 7
(N) is given a predetermined frequency characteristic, and the signal y
(N). The signal y (n) is output by the filter 7, changes in its frequency characteristics due to the external environment, and is taken into the microphone 12 as a signal h (n). That is, since the signal h (n) is obtained by adding the transfer characteristic H to the output signal y (n) of the filter 7, h (n) = H.x (n).

Further, the adder 61 calculates an error signal e such that e = h (n) -d (n), and supplies it to one input terminal of the parameter supply unit 62.

On the other hand, to the addition result x (n) supplied to the parameter supply unit 62, for example, the above-described estimated characteristic H 'of the transfer characteristic H is added by the estimated value giving unit 63 composed of a filter. . Here, the signal to which the estimation characteristic H ′ is added is defined as x ′ (n). Parameter supply unit 62
Calculates a coefficient w ′ (i) that minimizes the square of the error signal e from the error signal e and the signal x ′ (n) using the following equation, and supplies the coefficient w ′ (i) to each multiplier of the filter 7.

(Equation 3)

As a result, the characteristic of the filter 7 becomes D /
H ′, the output signal y (n) is y (n) = (D / H ′) × x (n). Further, y (n) output from the speaker 11
Has a transfer characteristic H, the signal h (n) captured by the microphone 12 is given by: h (n) = Hy (n) = H. (D / H '). X (n) Become. If the transfer characteristic H is accurately estimated as described above, then H / H ′ ≒ 1, so that h (n) ≒ D · x (n) ≒ d (n). Further, H / H ′ can be brought close to 1 by increasing the number of connected delay elements D, appropriately setting the value of μ, and the like.

Therefore, regardless of the transfer characteristic H due to the external environment, the tone reaching the microphone 12 has a frequency characteristic D corresponding to the genre code JC in the addition result x (n).
Is given. That is, the musical sound heard by the player has a desired frequency characteristic D.

In the above-described embodiment, the following modifications are possible. In the above-described embodiment, a monaural configuration is used. However, as shown in FIG. 6A, a stereo configuration having two speakers and two microphones may be used. In this figure, x
_R (n) and x _L (n) are the addition results x in FIG.
(N) is assigned to the R and L channels,
x _R (n) is applied to filters 7 _RR and 7 _RL and x _L (n)
Are supplied to the filters 7 _LR and 7 _LL , respectively. The filter 7 _RR gives the reverse characteristic of the transfer characteristic H _RR from the speaker 11R to the microphone 12R. Similarly, the filter 7 _RL has the transfer characteristic H _RL from the speaker 11 R to the microphone 12L, and the filter 7 _LR has the same. transfer characteristic H _LR from the speaker 11L to the microphone 12R, filter 7 _LL is to impart each of the transmission characteristic H _LL from the speaker 11L to the microphone 12L, each inverse characteristic. And the adder SR
, The outputs of the filters 7 _RR and 7 _LR are added, and the addition result is output from the speaker 12R. Similarly,
The outputs of the filters 7 _LR and 7 _LL are added in the adder SL, and the addition result is output from the speaker 12L. If the filters 7 _RR , 7 _RL , 7 _LR , 7 _LL and the transfer characteristics H _RR , H _RL , H _LR , H _LL are made to correspond to each other as in the above-described embodiment, the tone is stereo. be able to.

The frequency characteristics described above correspond to the genre code JC and are fixed, but may be arbitrarily set by the player. Furthermore, a plurality of settings may be made so that a desired one can be selected.

[0030]

According to the calling <br/> light according to claim 1 as described above, according to the present invention, the filter control means, so as to compensate the frequency characteristic changes due to indoor environment, controlling the frequency characteristics of the musical tone signal Therefore, it is possible to provide an electronic musical instrument in which a musical sound reaching a listener has a desired frequency characteristic.
Further, according to the present invention, a plurality of data relating to a desired frequency characteristic is stored, and arbitrary data can be selected from the data, and the selected data and the transfer characteristic estimated by the estimating means are determined. Since the filter coefficient is calculated and generated and supplied to the filter means, it is possible to give an arbitrary frequency characteristic to the musical sound, and to give an arbitrary frequency characteristic to the musical sound and a change in the frequency characteristic due to the indoor environment. Compensation can be realized with one filter, and the configuration can be simplified. Furthermore, according to the present invention, at the time of characteristic estimation, the tone signal generated by the tone signal generating means is output from the output means, and after the characteristic estimation is completed, the tone signal filtered by the filter means is output from the output means. Therefore, since the filter is not interposed at the time of characteristic estimation, unnecessary deterioration of the signal can be prevented. In addition, according to the first aspect of the present invention, the filter control means adjusts the transfer characteristic so that an error signal obtained from the signal output from the input means and the tone signal has a minimum value. Since the filter coefficient to be newly supplied to the filter means is calculated based on the data on the desired frequency characteristic, a desired frequency characteristic is given to the filter coefficient regardless of the transfer characteristic due to the external environment. A musical tone having a desired frequency characteristic reaches the performer. Further, according to the second aspect of the present invention,
If the filter control means outputs a signal from the input means,
Error signal obtained from the signal and the tone signal
Filter using the least-squares method so as to have a small value
In order to calculate the coefficients, the adaptation process using the least squares method
By minimizing the square of the error signal,
Data coefficients can be calculated. Further, according to the third aspect of the present invention,
According, the setting means is in the adaptation process of the filter coefficients
Convergence speed can be set arbitrarily.
In the process of adapting the filter coefficients, each filter coefficient
It is possible to set an appropriate convergence speed corresponding to. Ma
Further, according to the invention of claim 4, the stored
Performer performs from among multiple frequency characteristic data
You can select the ideal frequency characteristics of the music genre
Adds the desired frequency characteristics to the music that the performer listens to
can do.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment according to the present invention.

FIG. 2 is a schematic block diagram for explaining the operation of the embodiment.

FIG. 3 is a schematic block diagram for explaining the operation of the embodiment.

FIG. 4 is a plan view showing a detailed configuration of an operation panel 2 in the embodiment.

FIG. 5 is a block diagram showing a detailed configuration of a filter 7 in the embodiment.

FIG. 6 is a block diagram showing a main configuration of a modification of the present invention.

[Explanation of symbols]

3 ... tone signal generation unit (tone signal generation means), 5 ... data supply unit (target value supply means), 6 ... operation unit (filter control means), 7 ... filter (filter means), 11
... Speaker (output means), 12 ... Microphone (input means)

Claims (4)

(57) [Claims] 1. A musical sound generating apparatus for providing a musical sound signal generating means for generating a predetermined musical sound signal and imparting a desired frequency characteristic to the musical sound signal generated by said musical sound signal means. filter means for filtering said tone signal Te, one either the filtered tone signal by the tone signal and the filter means in occurrence of the tone signal generation means
Output means for outputting a tone based on a tone signal ; input means for inputting a tone by the output means and converting the tone into a signal; and prior to giving a desired frequency characteristic to the tone signal, the tone signal generating means. with a tone signal generated in supplying to said output means, a musical tone signal generated in the signal and the tone signal means output from said input means in response thereto
Estimating means for estimating a transfer characteristic based on the tone signal filtered by the filter means, and storing a plurality of data relating to a desired frequency characteristic, and based on data selected from the plurality of data. Data supply means for controlling the frequency characteristic of the tone signal generated by the tone signal generation means, and a tone signal filtered by the filter means being supplied to the output means, and a signal output from the input means accordingly. The signal output from the input unit and the signal whose frequency characteristic is controlled by the data supply unit, such that the error signal obtained from the signal whose frequency characteristic is controlled by the data supply unit is the minimum value. The musical tone to which the transfer characteristic estimated in advance by the estimating means is added.
And a filter control means for calculating and generating the filter coefficient from a tone signal generated by the signal generation means and supplying the filter coefficient to the filter means. 2. The tone generator according to claim 1, wherein said filter control means calculates and generates said filter coefficients by a least squares method. 3. A convergence speed setting means for arbitrarily setting a convergence speed of the filter coefficient, wherein the filter means sets the filter coefficient according to the convergence speed set by the convergence setting means. The musical tone generating apparatus according to claim 1, wherein the musical tone generating apparatus generates a tone signal. 4. The musical sound generator according to claim 1, wherein said data supply means selects frequency characteristic data corresponding to a genre from a plurality of stored frequency characteristic data.